// Copyright (c) 2014-2016, The Regents of the University of California.
// Copyright (c) 2016-2017, Nefeli Networks, Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice, this
// list of conditions and the following disclaimer.
//
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
//
// * Neither the names of the copyright holders nor the names of their
// contributors may be used to endorse or promote products derived from this
// software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.

#include "generic_decap.h"

CommandResponse GenericDecap::Init(const bess::pb::GenericDecapArg &arg) {
  if (arg.bytes() == 0) {
    return CommandSuccess();
  }
  decap_size_ = arg.bytes();
  if (decap_size_ <= 0 || decap_size_ > 1024) {
    return CommandFailure(EINVAL, "invalid decap size");
  }
  return CommandSuccess();
}

void GenericDecap::ProcessBatch(Context *ctx, bess::PacketBatch *batch) {
  int cnt = batch->cnt();

  int decap_size = decap_size_;

  for (int i = 0; i < cnt; i++) {
    batch->pkts()[i]->adj(decap_size);
  }

  RunNextModule(ctx, batch);
}

ADD_MODULE(GenericDecap, "generic_decap",
           "remove specified bytes from the beginning of packets")
